Hi!
I just had the same problem yesterday, I fixed it using Lineage Recovery instead of TWRP. Let me know if that doesn't work.
View attachment 5726313
@Benjamin1989 you should have read the
instructions 
if you wanna use TWRP then
@ceracz has made a dynamic
twrp that can be used to install LOS, Gapps, magisk etc BUT you still have to fastboot the super_empty.img from a computer (make sure your adb and fastboot commands are up to date. Once that is done if you have the files on an SD card in the phone you can install the usual way. The 'official' instructions he gave are :
LOS Flash procedure using TWRP
Clean flash:
1. Enter fastboot
2. Flash twrp recovery fastboot flash recovery recovery-3.6.2_12-pyxis-dynamic.img
3. Reboot to recovery (press volume-up and type fastboot reboot)
4.
DON'T enter password/gesture/pin (otherwise step 5 will fail)
5. Format data with yes
6. Reboot -> Bootloader
7. Flash super_empty fastboot wipe-super super_empty.img
8. Reboot to recovery (press volume-up and type fastboot reboot)
9. Copy LOS ROM, Gapps etc. to device by adb push
10. Flash LOS zip
11. Reboot to recovery (mandatory)
12. Flash Gapps and other zips
13. Reboot to system
For step 12 I highly recommend flashing the
safety-net-strict-addon.zip if you are using banking apps (I did it even though I had Magisk with Zygisk and deny list and hid the app, with Universal SafetyNet Fix and MagiskHide Props Config 1 app kept detecting root but after flashing the
safety-net-strict-addon.zip file all good

I used
MindTheGapps-12.1.0-arm64-20220605_112439.zip and everything is working great.